1. Field of the Invention
The present invention is broadly concerned with improved concrete form assemblies which can be readily erected in close quarters with adjacent, preexisting structures. More particularly, the invention is concerned with such form assemblies and the components thereof, which allow form erection and disassembly with as little as ½ inch clearance between the form and an adjacent building or the like.
2. Description of the Prior Art
Many present day poured concrete structures are constructed using prefabricated, reusable, interlocking form sections or panels. These panels are necessarily of relatively high strength, yet preferably are compact and lightweight. Thus, concrete form panels are advantageously constructed from aluminum, and are designed to be interconnected end-to-end as well as in opposed relationship, to present a wall form for example. For purposes of end-to-end interconnection, the panels generally include vertically extending end walls having a series of spaced openings therethrough. When placed in juxtaposition with the end wall apertures in alignment, the individual panels are typically interconnected by means of slotted pin and wedge assemblies. Thus, slotted pins are driven through aligned end wall apertures, and a wedge is then placed within the pin slot in order to lock the individual panels together. When the form is disassembled, the wedges are loosened and removed, and the pins extracted from the form panel apertures. Other types of form panel connection apparatus have been proposed, wherein the connectors are wholly or largely permanently affixed to the panels. See, e.g., U.S. Pat. Nos. 5,251,861 and 7,182,308.
Cross-connection of concrete form panels is often accomplished using what is referred to as “taper-tie” connectors. In such situations, a series of elongated connecting rods extend between opposed form panels and are secured at their outer ends by means of threaded fasteners. The inner portion of the connecting rods between the opposed form panels is covered with a tubular conical sleeve to permit extraction of the connection rods after a concrete wall is formed. These connecting rods are typically located at the central region of the form panels, rather than at the side margins thereof. This is because it is difficult to attach the connecting rod fasteners at the side margins, where the later form connection hardware is located. However, such central taper-tie assemblies can be difficult to install, and do not give maximum support at the critical joints between the form panels.
These existing concrete form assemblies require workmen access along the exterior surfaces of the separate form walls as they are erected. This in turn necessitates that a minimum clearance of several feet is required from existing structures and the like, in order to allow such access. In some instances, however, this degree of clearance is simply not available, making the form erection process very difficult if not impossible.
Other existing wall form assemblies for use in low-clearance situations are provided as unitary, elongated form structures, as opposed to a plurality of individual panels secured together. Such elongated wall sections may be set in place without need for workmen access along the exterior surfaces of the form. However, these wall sections are generally very heavy and require the use of a mechanical hoist (such as a crane) in order to be set in place.
There is accordingly a need in the art for improved concrete form assemblies which can be successfully hand-erected in very low clearance situations, while nonetheless providing stable and commercially reasonable complete forms.